Successful Deployment Strategies - Professional SQL Server 2005 Performance Tuning - page 526

Each of the features comes with a unique set of installation requirements. SQL Server Management
Tools require Windows client machines to be installed and are essential to managing and maintaining
a SQL 2005 Server environment. Similarly, SQL Server 2005 Reporting Services — a powerful reporting
tool — requires IIS to be installed. Thus, additional features add to the complexity of the design process
and may require understanding of components beyond the core database engine.

Best Practice
Beware of complexities when deploying additional features.

High Availability and Disaster Recovery
Along with sizing the database infrastructure, it is also important to incorporate high availability and
disaster recovery into the overall architecture design. A high availability SQL Server solution will mask
the effects of a hardware or software failure while ensuring that applications remain available and mini-
mizing downtime. However, before you select a high-availability solution, it is important to understand
the goals of this solution. SQL Server 2005 comes with several features that increase the availability of
production databases, but these features are different in terms of what they can achieve and typically
require additional infrastructure that will add to your cost of implementation. Before you start to design
your highly available SQL Server solution, you should answer some of the following questions to get a
sense of what features that you should deploy:

❑ Is failover going to be automatic or manual?

❑ Is a failure going to be detected automatically and appropriate action taken?

❑ Is Transparent Client Redirect important?

❑ How much downtime can you afford?

What is the typical size of your transaction logs?

❑

Where are the failover servers located? In the same datacenter, a different datacenter in the same
building, a different building, and so on.

❑

After you have answered some of these questions, it is much easier to pick the correct feature that will
help you achieve your high-availability goals.

Best Practice
Don't deploy high-availability features until you know what you want, to avoid dupli-
cating efforts.

Backup and Restore
Any good high-availability strategy must include detailed plans on backing up and restoring SQL Server
databases. SQL Server 2005 provides numerous ways to back up a database such as full, differential, log,